Helene Jensen, 16, says goodbye to her mother Winnie before boarding a flight to Newark, N.J., on her way to her native Denmark. A quirk in an immigration law will not allow her to stay with her parents in the United States.

Helene Jensen and her mother sobbed as they held each other one last time at Palm Beach International Airport.

"I'll be back. Don't worry," the 16-year-old Dwyer High School student whispered in her mother's ear. "I love you, too."

She stepped through a metal detector, turned and, her eyes glistening, covered her mouth with one hand and waved goodbye with the other. Then she was gone.

The Danish-born teen flew Thursday morning to Newark, N.J. By midnight, she was scheduled to be on her way across the Atlantic Ocean to Copenhagen with two months' worth of experimental medicine to keep her juvenile rheumatoid arthritis in check. She'll stay with her grandmother.

She promised to return but, in truth, her family is uncertain when that may happen.

If she had remained with her parents in Palm Beach Gardens, Helene would be an illegal alien today, facing possible deportation.

Through a quirk in immigration law, her parents are legal, her U.S.-born sister is legal, a Danish-born sister is legal because she has a work visa, but Helene is not.

In almost every instance, a child has the same immigration status as her parents, but not in this case. "It's really not logical. It flies in the face of public policy," said Maralyn Leaf, a Miami immigration lawyer who represents the Jensens.

U.S. Rep. Clay Shaw, R-Fort Lauderdale, is heading an effort by Florida congressmen to allow Helene back in the United States after inquiries to immigration officials did not change her status Thursday. Shaw's office has contacted State Department officials and the U.S. Embassy in Copenhagen to try to expedite Jensen's possible return, said Eric Eikenberg, Shaw's chief of staff.

U.S. Sen. Bob Graham, D-Fla., will seek a legislative correction to the law, but that will take time. "We've advised the family and had conversations with other legislators that clearly there's a problem with the law," said Paul Anderson, Graham's spokesman.

Helene's father, John Jensen, is a vice president of operations for Teeters Agency and Stevedoring at the Port of Palm Beach. He and his family have been in the United States since 1997 under a work visa.

That expired in March. An older American-born daughter is sponsoring John and his wife, Winnie, in their application to become permanent residents. They should get their green cards in a few months. In five years, they obtain citizenship.

But Helene is neither a spouse, parent or child of her sponsoring sister and would fall into a different category with a probable 6- to 7-year wait to become legal. She obtained a three-month visa waiver that expired Thursday.

Immigration officials said the Jensens have not officially sought to keep their daughter here.

"If the family had filed anything on behalf of Helene Jensen with the U.S. Department of Homeland Security, we would have been able to consider the matter. However, nothing was filed with our department," said Ana Santiago, spokeswoman for the U.S. Department of Citizenship and Immigration Services.

The Jensens' lawyer said they had considered the options, and the most likely to succeed required her to leave the country.

The Jensens will apply for a student visa when Helene arrives in Denmark. Then she could finish high school and attend college in the United States, long enough for her parents to become citizens and sponsor her.

If that fails, the Jensens will seek "humanitarian parole," available only after other options have been exhausted. Helene's painful disease forced her to use crutches until she enrolled in a trial program for a new drug being tested by Abbott Laboratories. The parole would allow her to continue in the drug trial, only available in the States. But the visa could expire when the drug trial ends.

"She was trying to be brave," her father said. "She didn't want to go. It's hard for a 16-year-old. They're all smiles and laughter, but when it comes to the moment, reality sets in. It's not fun and games anymore."